Disorders of the Immune Response Flashcards
what are the different types of hypersensitivity
- Type I: allergic reaction
- Type II: antibody (IgG) mediated
- Type II: immune complex hypersensitivity
- Type IV: cell mediated and cell mediated delayed hypersensitivity
allergic reaction s/s
- urticaria
- rhinitis
- atopic dermatitis
- bronchial asthma
causative mechanism of allergic reaction
allergen causes formation of IgE antibodies from B lymphocytes. They attach to mast cells upon re-exposure to the allergen, the allergen attaches to the IgE on the mast cells sausing the release of histamine. Histamine causes an inflammatory response
what is the exaggerated type I hypersensitivity reaction
Anaphylactic shock
Anaphylaxis
severe hypersensitivity reaction. Due to large amounts of chemical mediators released from mast cells into general circulation quickly
s/s of anaphylaxis
- Edema in mucosa
- Constriction of the bronchioles occurs obstructing airflow
- Hives
- Itching
- Skin erythema
- Vomiting
- Abdominal cramping
treatment of anaphylaxis
injection of epinephrine
what does injection of epinephrine do
- Causes vasoconstriction
- Increase the rate and strength of heartbeat
- Relaxes the bronchiole smooth muscle
type II hypersensitivity reaction
antibody (IgG) mediated
how many types of type II hypersensitivity reactions are there
3
type 1 of type II hypersensitivity reaction
complement and antibody mediated cell destruction
what are the examples of type 1 of type II
- drug reactionL hemolytic anemia from penicillin
- incompatible blood transfusion
type 2 of type II hypersensitivity reaction
complement and antibody mediated inflammation
what are the examples of type 2 of type II
rejecting organs
type 3 of type II hypersensitivity reaction
antibody mediated cellular activation or destruction
what are the examples of type 3 of type II
- graves disease: produce antibodies, they attach to receptors in thyroid gland, and thyroid gland releases large amounts of T3 and T4
- Myastenia gravis: binds to Ach receptor destroying the receptor
type III hypersensitivity reactions
immune complex hypersensitivity
what is immune complex hypersensitivity
antigen and antibody complex being deposited in the walls of blood vessels that causes an inflammation and damage to blood vessels
examples of immune complex hypersensitivity
- glomerulonephritis
- autoimmune vasculitis
s/s of immune complex hypersensitivity
- urticaria
- patchy or generalized rash
- extensive edema
- fever
type IV hypersensitivity reactions
cell mediated delayed hypersensitivity
cell mediated delayed hypersensitivity:
- cell mediated
- direct cell mediated cytotoxicity
- delayed type hypersensitivity
cell mediated
t lymphocytes attack antigen
direct cell mediated cytotoxicity
cytotoxic t cells directly kill antigen containing cell
Delayed type hypersensitivity
- takes a couple days for inflammation and adverse effect to happen
- response to soluble protein antigen
- macrophages, t helper cells
4 general category of transplant:
- allograft
- isograft
- autograft
- xenograft
allograft
same species
isograft
identical twins
autograft
one part of the body to another
xenograft
between different species
does allograft need immunosuppressive drugs and matching HLA/MHC’s
you have to match between 7-10 of the HLA and MHC - if someone is a good match it means their HLA are closely matched - they also have to be on immunosuprresive drugs
does isograft need immunosuppressive drugs and matching HLA/MHC’s
they have identical HLA/MHC, that is automatically a compatible transplant so there is no need for immunosuprressive drugs
does autograft need immunosuppressive drugs and matching HLA/MHC’s
identical HLA/MHC - no immunosuprresive drugs
does xenograft need immunosuppressive drugs and matching HLA/MHC’s
immunosuprresive drugs are needed
what are the different types of rejection in host vs graft disease
- hyperacute
- acute
- chronic
hyperacute reaction
occurs immediately after transplantation when blood flow is reestablished. Due to preexisting antibodies in the host. The blood vessels are affected and consequently blood flow to the transplanted organ is compromised
acute reaction
occurs several weeks after transplantation when unmatched antigens cause a reaction → generation of T cells, antibodies against the graft
Chronic reaction
occurs several months or years after transplantation. Blood vessels in the graft are gradually damaged
what is the process of graft vs. host disease
Occur when there are some T-lymphocytes in the graft that attack the host (host is immunologically compromised)
what are the three things you need for a graft vs host disease to occur
- Transplant must have a functional cellular immune component
- Recipient tissue must have antigens foreign to the donor T-lymphocytes
- Recipient immune system must be compromised to the point where it can’t destroy the transplanted T-cells
immunodeficiency
loss of part or all the function of immune system
Primary immunodeficiency
- Humoral (B-cell deficiencies) → hypogammaglobulinemia
- Cellular (T-cell) deficiencies →thymic aplasia
- Severe combined immunodeficiency disorder (SCID): deficient B and T cell due to non-functional T-helper cells → bubble boy disease
- Wiskott aldrich syndrome: production of abnormal or non functional immune cells → decreased antibody production
Secondary immunodeficiency
- Malnutrition
- Immunosuppressant drugs
- AIDS
- Kidney disease
- Hodgkin lymphoma
- Chemotherapy
What is the difference between being diagnosed HIV positive and being
diagnosed with AIDS?
The difference between being HIV+ or AIDS has to do with the number of T helper cells. If it’s below 200 you have AIDS and not HIV.
AIDS-Associated illnesses
- respiratory: pneumocytosis pneumonia, pulmonary TB
- gastrointestinal: esophageal candidiasis, CMV, herpes simplex
